In the conventional art, the method of peeling off and removing a resist film formed on a semiconductor wafer most broadly used is a method of ashing the resist film by exciting an ashing gas with electric discharge plasma. However, due to the heterogeneity and fluctuation or the like of a plasma electric field in this conventional ashing method, the heterogeneity in an electric field is developed on the wafer and it is difficult to obtain a homogeneous ashing performance. This results in a negative influence on the yield of the semiconductor device as a product. Further, it is difficult to produce a homogeneous plasma discharge over a large area, so that there are some drawbacks to the treatment of large-diameter semiconductor wafer.
As a peeling-off method for solving the above mentioned problems, there is already known the peeling-off method using the catalyst (for example, see a patent reference 1). In this peeling-off method, the catalyst such as a tungsten wire is arranged above the semiconductor wafer to be treated, and a reaction gas is cracked by heating the catalyst to a high temperature and bringing the reaction gas into contact with the catalyst of high temperature. Then, the peeling-off treatment is carried out by applying the cracked reaction gas to the wafer. Then, the peeling-off treatment is carried out by applying the cracked reaction gas to the wafer.
Patent reference 1: Japanese patent application publication No. 2000-294535.